E.ON retains a material ownership share and will be responsible for the day-to-day operation of the wind farms. The power generated by these wind farms over the next 15 years has been sold to a number of US utilities companies at a fixed price.

PensionDanmark became the first pension fund to invest directly in offshore wind when it acquired a 50% stake in Dong Energy's 166MW Nysted wind farm late 2010. This was followed by the joint investment with fellow Danish pension fund PKA in 2011 in a 50% stake in Dong Energy's 400MW Aanholt wind farm, currently under construction in Danish waters.

Speaking to Windpower Monthly last month before details of the E.ON US deal were made public, PensionDanmark CEO Torben Möger Pedersen said his firm expected to use its "experiences with our initial investments in Danish offshore wind farms to invest in other energy-related infrastructure projects in Europe and North America".

Today, following the announcement of the E.ON deal, Pedersen said PensionDanmark's investments in Denmark and the US would "provide a stable and attractive return at a level very similar to what you can expect from equities, but with a significant less risk and [exposure] to the business cycle".

He added that PensionDanmark would "continue to focus strongly on investment of this type". The pension fund is seeking to increase its investments in stable alternatives, such as various types of infrastructure, to around 10% of its assets. The aim is to invest a further $2 billion in infrastructure over the next five years.

For its part, E.ON sees tpday's deal as the first of many within a strategy of trying to free up capital in operational assets to fund new projects.

"This transaction is an important step to implementing our strategy to generate more value with the use of less capital," said E.ON CFO Marcus Schenck.

"Further transactions are likely to follow."

The final transaction between E.ON and PensionDanmark is subject to regulatory approval and financing arrangements.